1 /* crypto/rsa/rsa_eay.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/rand.h>
64 #ifndef OPENSSL_NO_ENGINE
65 #include <openssl/engine.h>
70 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
71 unsigned char *to, RSA *rsa,int padding);
72 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
73 unsigned char *to, RSA *rsa,int padding);
74 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
75 unsigned char *to, RSA *rsa,int padding);
76 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
77 unsigned char *to, RSA *rsa,int padding);
78 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *i, RSA *rsa);
79 static int RSA_eay_init(RSA *rsa);
80 static int RSA_eay_finish(RSA *rsa);
81 static RSA_METHOD rsa_pkcs1_eay_meth={
82 "Eric Young's PKCS#1 RSA",
83 RSA_eay_public_encrypt,
84 RSA_eay_public_decrypt, /* signature verification */
85 RSA_eay_private_encrypt, /* signing */
86 RSA_eay_private_decrypt,
88 BN_mod_exp_mont, /* XXX probably we should not use Montgomery if e == 3 */
98 const RSA_METHOD *RSA_PKCS1_SSLeay(void)
100 return(&rsa_pkcs1_eay_meth);
103 /* Static helper to reduce oodles of code duplication. As a slight
104 * optimisation, the "MONT_HELPER() macro must be used as front-end to this
105 * function, to prevent unnecessary function calls - there is an initial test
106 * that is performed by the macro-generated code. */
107 static int rsa_eay_mont_helper(BN_MONT_CTX **ptr, const BIGNUM *modulus, BN_CTX *ctx)
109 BN_MONT_CTX *bn_mont_ctx;
110 if((bn_mont_ctx = BN_MONT_CTX_new()) == NULL)
112 if(!BN_MONT_CTX_set(bn_mont_ctx, modulus, ctx))
114 BN_MONT_CTX_free(bn_mont_ctx);
117 if (*ptr == NULL) /* other thread may have finished first */
119 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
120 if (*ptr == NULL) /* check again in the lock to stop races */
125 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
128 BN_MONT_CTX_free(bn_mont_ctx);
132 * MONT_HELPER(rsa, bn_ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
134 #define MONT_HELPER(rsa, ctx, m, pre_cond, err_instr) \
135 if((pre_cond) && ((rsa)->_method_mod_##m == NULL) && \
136 !rsa_eay_mont_helper(&((rsa)->_method_mod_##m), \
140 static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
141 unsigned char *to, RSA *rsa, int padding)
144 int i,j,k,num=0,r= -1;
145 unsigned char *buf=NULL;
150 if ((ctx=BN_CTX_new()) == NULL) goto err;
151 num=BN_num_bytes(rsa->n);
152 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
154 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
160 case RSA_PKCS1_PADDING:
161 i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
163 #ifndef OPENSSL_NO_SHA
164 case RSA_PKCS1_OAEP_PADDING:
165 i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
168 case RSA_SSLV23_PADDING:
169 i=RSA_padding_add_SSLv23(buf,num,from,flen);
172 i=RSA_padding_add_none(buf,num,from,flen);
175 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
178 if (i <= 0) goto err;
180 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
182 if (BN_ucmp(&f, rsa->n) >= 0)
184 /* usually the padding functions would catch this */
185 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
189 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
191 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
192 rsa->_method_mod_n)) goto err;
194 /* put in leading 0 bytes if the number is less than the
195 * length of the modulus */
196 j=BN_num_bytes(&ret);
197 i=BN_bn2bin(&ret,&(to[num-j]));
198 for (k=0; k<(num-i); k++)
203 if (ctx != NULL) BN_CTX_free(ctx);
208 OPENSSL_cleanse(buf,num);
214 static int rsa_eay_blinding(RSA *rsa, BN_CTX *ctx)
217 CRYPTO_w_lock(CRYPTO_LOCK_RSA);
218 /* Check again inside the lock - the macro's check is racey */
219 if(rsa->blinding == NULL)
220 ret = RSA_blinding_on(rsa, ctx);
221 CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
225 #define BLINDING_HELPER(rsa, ctx, err_instr) \
227 if((!((rsa)->flags & RSA_FLAG_NO_BLINDING)) && \
228 ((rsa)->blinding == NULL) && \
229 !rsa_eay_blinding(rsa, ctx)) \
234 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
235 unsigned char *to, RSA *rsa, int padding)
238 int i,j,k,num=0,r= -1;
239 unsigned char *buf=NULL;
245 if ((ctx=BN_CTX_new()) == NULL) goto err;
246 num=BN_num_bytes(rsa->n);
247 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
249 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
255 case RSA_PKCS1_PADDING:
256 i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
259 i=RSA_padding_add_none(buf,num,from,flen);
261 case RSA_SSLV23_PADDING:
263 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
266 if (i <= 0) goto err;
268 if (BN_bin2bn(buf,num,&f) == NULL) goto err;
270 if (BN_ucmp(&f, rsa->n) >= 0)
272 /* usually the padding functions would catch this */
273 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
277 BLINDING_HELPER(rsa, ctx, goto err;);
279 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
280 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
282 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
285 (rsa->dmp1 != NULL) &&
286 (rsa->dmq1 != NULL) &&
287 (rsa->iqmp != NULL)) )
288 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
291 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
292 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
293 rsa->_method_mod_n)) goto err;
296 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
297 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
299 /* put in leading 0 bytes if the number is less than the
300 * length of the modulus */
301 j=BN_num_bytes(&ret);
302 i=BN_bn2bin(&ret,&(to[num-j]));
303 for (k=0; k<(num-i); k++)
308 if (ctx != NULL) BN_CTX_free(ctx);
313 OPENSSL_cleanse(buf,num);
319 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
320 unsigned char *to, RSA *rsa, int padding)
325 unsigned char *buf=NULL;
331 if (ctx == NULL) goto err;
333 num=BN_num_bytes(rsa->n);
335 if ((buf=(unsigned char *)OPENSSL_malloc(num)) == NULL)
337 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
341 /* This check was for equality but PGP does evil things
342 * and chops off the top '0' bytes */
345 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
349 /* make data into a big number */
350 if (BN_bin2bn(from,(int)flen,&f) == NULL) goto err;
352 if (BN_ucmp(&f, rsa->n) >= 0)
354 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
358 BLINDING_HELPER(rsa, ctx, goto err;);
360 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
361 if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) goto err;
364 if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
367 (rsa->dmp1 != NULL) &&
368 (rsa->dmq1 != NULL) &&
369 (rsa->iqmp != NULL)) )
370 { if (!rsa->meth->rsa_mod_exp(&ret,&f,rsa)) goto err; }
373 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
374 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,
379 if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
380 if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
383 j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
387 case RSA_PKCS1_PADDING:
388 r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
390 #ifndef OPENSSL_NO_SHA
391 case RSA_PKCS1_OAEP_PADDING:
392 r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
395 case RSA_SSLV23_PADDING:
396 r=RSA_padding_check_SSLv23(to,num,buf,j,num);
399 r=RSA_padding_check_none(to,num,buf,j,num);
402 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
406 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
409 if (ctx != NULL) BN_CTX_free(ctx);
414 OPENSSL_cleanse(buf,num);
420 /* signature verification */
421 static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
422 unsigned char *to, RSA *rsa, int padding)
427 unsigned char *buf=NULL;
433 if (ctx == NULL) goto err;
435 num=BN_num_bytes(rsa->n);
436 buf=(unsigned char *)OPENSSL_malloc(num);
439 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
443 /* This check was for equality but PGP does evil things
444 * and chops off the top '0' bytes */
447 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
451 if (BN_bin2bn(from,flen,&f) == NULL) goto err;
453 if (BN_ucmp(&f, rsa->n) >= 0)
455 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
459 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
461 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->e,rsa->n,ctx,
462 rsa->_method_mod_n)) goto err;
469 case RSA_PKCS1_PADDING:
470 r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
473 r=RSA_padding_check_none(to,num,buf,i,num);
476 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
480 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);
483 if (ctx != NULL) BN_CTX_free(ctx);
488 OPENSSL_cleanse(buf,num);
494 static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
503 if ((ctx=BN_CTX_new()) == NULL) goto err;
505 MONT_HELPER(rsa, ctx, p, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
506 MONT_HELPER(rsa, ctx, q, rsa->flags & RSA_FLAG_CACHE_PRIVATE, goto err);
507 MONT_HELPER(rsa, ctx, n, rsa->flags & RSA_FLAG_CACHE_PUBLIC, goto err);
509 if (!BN_mod(&r1,I,rsa->q,ctx)) goto err;
510 if (!rsa->meth->bn_mod_exp(&m1,&r1,rsa->dmq1,rsa->q,ctx,
511 rsa->_method_mod_q)) goto err;
513 if (!BN_mod(&r1,I,rsa->p,ctx)) goto err;
514 if (!rsa->meth->bn_mod_exp(r0,&r1,rsa->dmp1,rsa->p,ctx,
515 rsa->_method_mod_p)) goto err;
517 if (!BN_sub(r0,r0,&m1)) goto err;
518 /* This will help stop the size of r0 increasing, which does
519 * affect the multiply if it optimised for a power of 2 size */
521 if (!BN_add(r0,r0,rsa->p)) goto err;
523 if (!BN_mul(&r1,r0,rsa->iqmp,ctx)) goto err;
524 if (!BN_mod(r0,&r1,rsa->p,ctx)) goto err;
525 /* If p < q it is occasionally possible for the correction of
526 * adding 'p' if r0 is negative above to leave the result still
527 * negative. This can break the private key operations: the following
528 * second correction should *always* correct this rare occurrence.
529 * This will *never* happen with OpenSSL generated keys because
530 * they ensure p > q [steve]
533 if (!BN_add(r0,r0,rsa->p)) goto err;
534 if (!BN_mul(&r1,r0,rsa->q,ctx)) goto err;
535 if (!BN_add(r0,&r1,&m1)) goto err;
537 if (rsa->e && rsa->n)
539 if (!rsa->meth->bn_mod_exp(&vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
540 /* If 'I' was greater than (or equal to) rsa->n, the operation
541 * will be equivalent to using 'I mod n'. However, the result of
542 * the verify will *always* be less than 'n' so we don't check
543 * for absolute equality, just congruency. */
544 if (!BN_sub(&vrfy, &vrfy, I)) goto err;
545 if (!BN_mod(&vrfy, &vrfy, rsa->n, ctx)) goto err;
546 if (BN_get_sign(&vrfy))
547 if (!BN_add(&vrfy, &vrfy, rsa->n)) goto err;
548 if (!BN_is_zero(&vrfy))
549 /* 'I' and 'vrfy' aren't congruent mod n. Don't leak
550 * miscalculated CRT output, just do a raw (slower)
551 * mod_exp and return that instead. */
552 if (!rsa->meth->bn_mod_exp(r0,I,rsa->d,rsa->n,ctx,
553 rsa->_method_mod_n)) goto err;
559 BN_clear_free(&vrfy);
564 static int RSA_eay_init(RSA *rsa)
566 rsa->flags|=RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE;
570 static int RSA_eay_finish(RSA *rsa)
572 if (rsa->_method_mod_n != NULL)
573 BN_MONT_CTX_free(rsa->_method_mod_n);
574 if (rsa->_method_mod_p != NULL)
575 BN_MONT_CTX_free(rsa->_method_mod_p);
576 if (rsa->_method_mod_q != NULL)
577 BN_MONT_CTX_free(rsa->_method_mod_q);